backup wip

This commit is contained in:
Alexander Soare 2024-04-03 19:23:22 +01:00
parent 110ac5ffa1
commit 278336a39a
3 changed files with 185 additions and 253 deletions

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@ -4,7 +4,7 @@ import torch
from torch import nn
from .backbone import build_backbone
from .transformer import TransformerEncoder, TransformerEncoderLayer, build_transformer
from .transformer import Transformer, TransformerEncoder
def get_sinusoid_encoding_table(n_position, d_hid):
@ -124,16 +124,14 @@ class ActionChunkingTransformer(nn.Module):
robot_state_embed = self.vae_encoder_robot_state_input_proj(robot_state).unsqueeze(1) # (B, 1, D)
action_embed = self.vae_encoder_action_input_proj(actions) # (B, S, D)
vae_encoder_input = torch.cat([cls_embed, robot_state_embed, action_embed], axis=1) # (B, S+2, D)
vae_encoder_input = vae_encoder_input.permute(1, 0, 2) # (S+2, B, D)
# Note: detach() shouldn't be necessary but leaving it the same as the original code just in case.
# Prepare fixed positional embedding.
pos_embed = self.vae_encoder_pos_enc.clone().detach().permute(1, 0, 2) # (S+2, 1, D)
pos_embed = self.vae_encoder_pos_enc.clone().detach() # (1, S+2, D)
# Forward pass through VAE encoder and sample the latent with the reparameterization trick.
vae_encoder_output = self.vae_encoder(
vae_encoder_input, pos=pos_embed
) # , src_key_padding_mask=is_pad) # TODO(now)
vae_encoder_output = vae_encoder_output[0] # take cls output only
latent_pdf_params = self.vae_encoder_latent_output_proj(vae_encoder_output)
cls_token_out = self.vae_encoder(
vae_encoder_input.permute(1, 0, 2), pos=pos_embed.permute(1, 0, 2)
)[0] # (B, D)
latent_pdf_params = self.vae_encoder_latent_output_proj(cls_token_out)
mu = latent_pdf_params[:, : self.latent_dim]
logvar = latent_pdf_params[:, self.latent_dim :]
# Use reparameterization trick to sample from the latent's PDF.
@ -151,10 +149,11 @@ class ActionChunkingTransformer(nn.Module):
all_cam_pos = []
for cam_id, _ in enumerate(self.camera_names):
# TODO(now): remove the positional embedding from the backbones.
features, pos = self.backbones[0](image[:, cam_id]) # HARDCODED
features = features[0] # take the last layer feature
cam_features, pos = self.backbones[0](image[:, cam_id]) # HARDCODED
cam_features = cam_features[0] # take the last layer feature
pos = pos[0]
all_cam_features.append(self.encoder_img_feat_input_proj(features))
cam_features = self.encoder_img_feat_input_proj(cam_features) # (B, C, h, w)
all_cam_features.append(cam_features)
all_cam_pos.append(pos)
# Concatenate image observation feature maps along the width dimension.
transformer_input = torch.cat(all_cam_features, axis=3)
@ -163,36 +162,25 @@ class ActionChunkingTransformer(nn.Module):
robot_state_embed = self.encoder_robot_state_input_proj(robot_state)
latent_embed = self.encoder_latent_input_proj(latent_sample)
# TODO(now): Explain all of this madness.
transformer_input = torch.cat(
[
torch.stack([latent_embed, robot_state_embed], axis=0),
transformer_input.flatten(2).permute(2, 0, 1),
]
)
pos_embed = torch.cat(
[self.additional_pos_embed.weight.unsqueeze(1), pos.flatten(2).permute(2, 0, 1)], axis=0
)
# Run the transformer and project the outputs to the action space.
transformer_output = self.transformer(
transformer_input,
query_embed=self.decoder_pos_embed.weight,
pos_embed=pos,
latent_input=latent_embed,
proprio_input=robot_state_embed,
additional_pos_embed=self.additional_pos_embed.weight,
)
a_hat = self.action_head(transformer_output)
return a_hat, [mu, logvar]
def build_vae_encoder(args):
d_model = args.hidden_dim # 256
dropout = args.dropout # 0.1
nhead = args.nheads # 8
dim_feedforward = args.dim_feedforward # 2048
num_encoder_layers = args.enc_layers # 4 # TODO shared with VAE decoder
normalize_before = args.pre_norm # False
activation = "relu"
encoder_layer = TransformerEncoderLayer(
d_model, nhead, dim_feedforward, dropout, activation, normalize_before
)
encoder_norm = nn.LayerNorm(d_model) if normalize_before else None
encoder = TransformerEncoder(encoder_layer, num_encoder_layers, encoder_norm)
return encoder
encoder_pos=pos_embed,
decoder_pos=self.decoder_pos_embed.weight.unsqueeze(1),
).transpose(0, 1) # back to (B, S, C)
actions = self.action_head(transformer_output)
return actions, [mu, logvar]
def build(args):
@ -203,9 +191,26 @@ def build(args):
backbone = build_backbone(args)
backbones.append(backbone)
transformer = build_transformer(args)
transformer = Transformer(
d_model=args.hidden_dim,
dropout=args.dropout,
nhead=args.nheads,
dim_feedforward=args.dim_feedforward,
num_encoder_layers=args.enc_layers,
num_decoder_layers=args.dec_layers,
normalize_before=args.pre_norm,
)
vae_encoder = build_vae_encoder(args)
# TODO(now): args.enc_layers shouldn't be shared with the transformer decoder
vae_encoder = TransformerEncoder(
num_layers=args.enc_layers,
d_model=args.hidden_dim,
nhead=args.nheads,
dim_feedforward=args.dim_feedforward,
dropout=args.dropout,
activation="relu",
normalize_before=args.pre_norm,
)
model = ActionChunkingTransformer(
backbones,

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@ -1,13 +1,7 @@
"""
DETR Transformer class.
Copy-paste from torch.nn.Transformer with modifications:
* positional encodings are passed in MHattention
* extra LN at the end of encoder is removed
* decoder returns a stack of activations from all decoding layers
TODO(now)
"""
import copy
from typing import Optional
import torch
@ -28,117 +22,68 @@ class Transformer(nn.Module):
normalize_before=False,
):
super().__init__()
encoder_layer = TransformerEncoderLayer(
d_model, nhead, dim_feedforward, dropout, activation, normalize_before
self.encoder = TransformerEncoder(
num_encoder_layers, d_model, nhead, dim_feedforward, dropout, activation, normalize_before
)
encoder_norm = nn.LayerNorm(d_model) if normalize_before else None
self.encoder = TransformerEncoder(encoder_layer, num_encoder_layers, encoder_norm)
decoder_layer = TransformerDecoderLayer(
d_model, nhead, dim_feedforward, dropout, activation, normalize_before
self.decoder = TransformerDecoder(
num_decoder_layers, d_model, nhead, dim_feedforward, dropout, activation, normalize_before
)
decoder_norm = nn.LayerNorm(d_model)
self.decoder = TransformerDecoder(decoder_layer, num_decoder_layers, decoder_norm)
self._reset_parameters()
self.d_model = d_model
self.nhead = nhead
self._init_params() # TODO(now): move to somewhere common
def _reset_parameters(self):
def _init_params(self):
for p in self.parameters():
if p.dim() > 1:
nn.init.xavier_uniform_(p)
def forward(
self,
src,
query_embed,
pos_embed,
latent_input=None,
proprio_input=None,
additional_pos_embed=None,
):
def forward(self, x, encoder_pos, decoder_pos):
"""
Args:
x: ((E)ncoder (S)equence, (B)atch, (C)hannels)
decoder_pos: (Decoder Sequence, C) tensor for the decoder's positional embedding.
encoder_pos: (ES, C) tenso
"""
# TODO flatten only when input has H and W
if len(src.shape) == 4: # has H and W
# flatten NxCxHxW to HWxNxC
bs, c, h, w = src.shape
# Each "pixel" on the feature maps will form a token.
src = src.flatten(2).permute(2, 0, 1)
pos_embed = pos_embed.flatten(2).permute(2, 0, 1).repeat(1, bs, 1)
query_embed = query_embed.unsqueeze(1).repeat(1, bs, 1)
bs = x.shape[1]
additional_pos_embed = additional_pos_embed.unsqueeze(1).repeat(1, bs, 1) # seq, bs, dim
pos_embed = torch.cat([additional_pos_embed, pos_embed], axis=0)
addition_input = torch.stack([latent_input, proprio_input], axis=0)
src = torch.cat([addition_input, src], axis=0)
else:
assert len(src.shape) == 3
# flatten NxHWxC to HWxNxC
bs, hw, c = src.shape
src = src.permute(1, 0, 2)
pos_embed = pos_embed.unsqueeze(1).repeat(1, bs, 1)
query_embed = query_embed.unsqueeze(1).repeat(1, bs, 1)
tgt = torch.zeros_like(query_embed)
memory = self.encoder(src, pos=pos_embed)
hs = self.decoder(tgt, memory, pos=pos_embed, query_pos=query_embed)
hs = hs.transpose(0, 1)
return hs
encoder_out = self.encoder(x, pos=encoder_pos)
decoder_in = torch.zeros(
(decoder_pos.shape[0], bs, decoder_pos.shape[2]),
dtype=decoder_pos.dtype,
device=decoder_pos.device,
)
decoder_out = self.decoder(decoder_in, encoder_out, encoder_pos=encoder_pos, decoder_pos=decoder_pos)
return decoder_out
class TransformerEncoder(nn.Module):
def __init__(self, encoder_layer, num_layers, norm=None):
super().__init__()
self.layers = _get_clones(encoder_layer, num_layers)
self.num_layers = num_layers
self.norm = norm
def forward(
def __init__(
self,
src,
pos: Optional[Tensor] = None,
num_layers,
d_model,
nhead,
dim_feedforward=2048,
dropout=0.1,
activation="relu",
normalize_before=False,
):
output = src
for layer in self.layers:
output = layer(output, pos=pos)
if self.norm is not None:
output = self.norm(output)
return output
class TransformerDecoder(nn.Module):
def __init__(self, decoder_layer, num_layers, norm=None):
super().__init__()
self.layers = _get_clones(decoder_layer, num_layers)
self.num_layers = num_layers
self.norm = norm
def forward(
self,
tgt,
memory,
pos: Optional[Tensor] = None,
query_pos: Optional[Tensor] = None,
):
output = tgt
self.layers = nn.ModuleList(
[
TransformerEncoderLayer(
d_model, nhead, dim_feedforward, dropout, activation, normalize_before
)
for _ in range(num_layers)
]
)
self.norm = nn.LayerNorm(d_model) if normalize_before else nn.Identity()
def forward(self, x, pos: Optional[Tensor] = None):
for layer in self.layers:
output = layer(
output,
memory,
pos=pos,
query_pos=query_pos,
)
if self.norm is not None:
output = self.norm(output)
return output
x = layer(x, pos=pos)
x = self.norm(x)
return x
class TransformerEncoderLayer(nn.Module):
@ -160,45 +105,55 @@ class TransformerEncoderLayer(nn.Module):
self.activation = _get_activation_fn(activation)
self.normalize_before = normalize_before
def with_pos_embed(self, tensor, pos: Optional[Tensor]):
return tensor if pos is None else tensor + pos
def forward_post(
self,
src,
pos: Optional[Tensor] = None,
):
q = k = self.with_pos_embed(src, pos)
src2 = self.self_attn(q, k, value=src)[0]
src = src + self.dropout1(src2)
src = self.norm1(src)
src2 = self.linear2(self.dropout(self.activation(self.linear1(src))))
src = src + self.dropout2(src2)
src = self.norm2(src)
return src
def forward_pre(
self,
src,
pos: Optional[Tensor] = None,
):
src2 = self.norm1(src)
q = k = self.with_pos_embed(src2, pos)
src2 = self.self_attn(q, k, value=src2)[0]
src = src + self.dropout1(src2)
src2 = self.norm2(src)
src2 = self.linear2(self.dropout(self.activation(self.linear1(src2))))
src = src + self.dropout2(src2)
return src
def forward(
self,
src,
pos: Optional[Tensor] = None,
):
def forward(self, x, pos: Optional[Tensor] = None):
skip = x
if self.normalize_before:
return self.forward_pre(src, pos)
return self.forward_post(src, pos)
x = self.norm1(x)
q = k = x if pos is None else x + pos
x = self.self_attn(q, k, value=x)[0]
x = skip + self.dropout1(x)
if self.normalize_before:
skip = x
x = self.norm2(x)
else:
x = self.norm1(x)
skip = x
x = self.linear2(self.dropout(self.activation(self.linear1(x))))
x = skip + self.dropout2(x)
if not self.normalize_before:
x = self.norm2(x)
return x
class TransformerDecoder(nn.Module):
def __init__(
self,
num_layers,
d_model,
nhead,
dim_feedforward=2048,
dropout=0.1,
activation="relu",
normalize_before=False,
):
super().__init__()
self.layers = nn.ModuleList(
[
TransformerDecoderLayer(
d_model, nhead, dim_feedforward, dropout, activation, normalize_before
)
for _ in range(num_layers)
]
)
self.num_layers = num_layers
self.norm = nn.LayerNorm(d_model)
def forward(self, x, encoder_out, decoder_pos: Tensor | None = None, encoder_pos: Tensor | None = None):
for layer in self.layers:
x = layer(x, encoder_out, decoder_pos=decoder_pos, encoder_pos=encoder_pos)
if self.norm is not None:
x = self.norm(x)
return x
class TransformerDecoderLayer(nn.Module):
@ -223,86 +178,55 @@ class TransformerDecoderLayer(nn.Module):
self.activation = _get_activation_fn(activation)
self.normalize_before = normalize_before
def with_pos_embed(self, tensor, pos: Optional[Tensor]):
def maybe_add_pos_embed(self, tensor: Tensor, pos: Tensor | None) -> Tensor:
return tensor if pos is None else tensor + pos
def forward_post(
self,
tgt,
memory,
pos: Optional[Tensor] = None,
query_pos: Optional[Tensor] = None,
):
q = k = self.with_pos_embed(tgt, query_pos)
tgt2 = self.self_attn(q, k, value=tgt)[0]
tgt = tgt + self.dropout1(tgt2)
tgt = self.norm1(tgt)
tgt2 = self.multihead_attn(
query=self.with_pos_embed(tgt, query_pos),
key=self.with_pos_embed(memory, pos),
value=memory,
)[0]
tgt = tgt + self.dropout2(tgt2)
tgt = self.norm2(tgt)
tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt))))
tgt = tgt + self.dropout3(tgt2)
tgt = self.norm3(tgt)
return tgt
def forward_pre(
self,
tgt,
memory,
pos: Optional[Tensor] = None,
query_pos: Optional[Tensor] = None,
):
tgt2 = self.norm1(tgt)
q = k = self.with_pos_embed(tgt2, query_pos)
tgt2 = self.self_attn(q, k, value=tgt2)[0]
tgt = tgt + self.dropout1(tgt2)
tgt2 = self.norm2(tgt)
tgt2 = self.multihead_attn(
query=self.with_pos_embed(tgt2, query_pos),
key=self.with_pos_embed(memory, pos),
value=memory,
)[0]
tgt = tgt + self.dropout2(tgt2)
tgt2 = self.norm3(tgt)
tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt2))))
tgt = tgt + self.dropout3(tgt2)
return tgt
def forward(
self,
tgt,
memory,
pos: Optional[Tensor] = None,
query_pos: Optional[Tensor] = None,
):
x: Tensor,
encoder_out: Tensor,
decoder_pos: Tensor | None = None,
encoder_pos: Tensor | None = None,
) -> Tensor:
"""
Args:
x: (Decoder Sequence, Batch, Channel) tensor of input tokens.
encoder_out: (Encoder Sequence, B, C) output features from the last layer of the encoder we are
cross-attending with.
decoder_pos: (ES, 1, C) positional embedding for keys (from the encoder).
encoder_pos: (DS, 1, C) Positional_embedding for the queries (from the decoder).
Returns:
(DS, B, C) tensor of decoder output features.
"""
skip = x
if self.normalize_before:
return self.forward_pre(
tgt,
memory,
pos,
query_pos,
)
return self.forward_post(tgt, memory, pos, query_pos)
def _get_clones(module, n):
return nn.ModuleList([copy.deepcopy(module) for _ in range(n)])
def build_transformer(args):
return Transformer(
d_model=args.hidden_dim,
dropout=args.dropout,
nhead=args.nheads,
dim_feedforward=args.dim_feedforward,
num_encoder_layers=args.enc_layers,
num_decoder_layers=args.dec_layers,
normalize_before=args.pre_norm,
)
x = self.norm1(x)
q = k = self.maybe_add_pos_embed(x, decoder_pos)
x = self.self_attn(q, k, value=x)[0]
x = skip + self.dropout1(x)
if self.normalize_before:
skip = x
x = self.norm2(x)
else:
x = self.norm1(x)
skip = x
x = self.multihead_attn(
query=self.maybe_add_pos_embed(x, decoder_pos),
key=self.maybe_add_pos_embed(encoder_out, encoder_pos),
value=encoder_out,
)[0]
x = skip + self.dropout2(x)
if self.normalize_before:
skip = x
x = self.norm3(x)
else:
x = self.norm2(x)
skip = x
x = self.linear2(self.dropout(self.activation(self.linear1(x))))
x = skip + self.dropout3(x)
if not self.normalize_before:
x = self.norm3(x)
return x
def _get_activation_fn(activation):
@ -313,4 +237,4 @@ def _get_activation_fn(activation):
return F.gelu
if activation == "glu":
return F.glu
raise RuntimeError(f"activation should be relu/gelu, not {activation}.")
raise RuntimeError(f"activation should be relu/gelu/glu, not {activation}.")

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@ -101,3 +101,6 @@ enable = true
[build-system]
requires = ["poetry-core>=1.0.0", "poetry-dynamic-versioning>=1.0.0,<2.0.0"]
build-backend = "poetry_dynamic_versioning.backend"
[tool.black]
line-length = 110